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Creates a method object for difference-in-differences augmented IPW estimation with external control borrowing for the open-label extension phase (Zhou et al., 2024).

Usage

did_ec_aipw(
  ps_formula,
  trt_formula = "",
  outcome_formula,
  bootstrap = 500L,
  bootstrap_ci_type = NULL
)

Arguments

ps_formula

Formula string for the propensity score model predicting trial participation.

trt_formula

Formula string for the treatment assignment model, or "" for marginal probability.

outcome_formula

Character vector of outcome model formulas, one per time point.

bootstrap

Number of bootstrap replicates. Defaults to 500.

bootstrap_ci_type

Bootstrap CI type. Defaults to "perc".

Value

An S4 object of class did_ec_aipw_method.

References

Zhou et al. (2024). Estimating treatment effect in randomized trial after control to treatment crossover using external controls. Journal of Biopharmaceutical Statistics. doi:10.1080/10543406.2024.2444222

Examples

did_ec_aipw(
  ps_formula = "S ~ x1 + x2 + x3 + x4 + x5",
  trt_formula = "A ~ x1 + x2 + x3 + x4 + x5",
  outcome_formula = c(
    "y1 ~ x1 + x2 + x3 + x4 + x5",
    "y2 ~ x1 + x2 + x3 + x4 + x5",
    "y3 ~ x1 + x2 + x3 + x4 + x5",
    "y4 ~ x1 + x2 + x3 + x4 + x5"
  ),
  bootstrap = 500
)
#> An object of class "did_ec_aipw_method"
#> Slot "ps_formula":
#> [1] "S ~ x1 + x2 + x3 + x4 + x5"
#> 
#> Slot "trt_formula":
#> [1] "A ~ x1 + x2 + x3 + x4 + x5"
#> 
#> Slot "outcome_formula":
#> [1] "y1 ~ x1 + x2 + x3 + x4 + x5" "y2 ~ x1 + x2 + x3 + x4 + x5"
#> [3] "y3 ~ x1 + x2 + x3 + x4 + x5" "y4 ~ x1 + x2 + x3 + x4 + x5"
#> 
#> Slot "bootstrap":
#> [1] 500
#> 
#> Slot "bootstrap_ci_type":
#> [1] "perc"
#> 
#> Slot "bootstrap_flag":
#> [1] TRUE
#> 
#> Slot "bootstrap_obj":
#> <bootstrap_obj>
#>   Replicates: 500 
#>   CI type: Percentile 
#> 
#> Slot "model_form_piS":
#> [1] ""
#> 
#> Slot "model_form_piA":
#> [1] ""
#> 
#> Slot "model_form_mu0_ext":
#> [1] ""
#> 
#> Slot "model_form_mu0_rct":
#> [1] ""
#> 
#> Slot "model_form_mu1_rct":
#> [1] ""
#> 
#> Slot "method_name":
#> [1] "DID-EC-AIPW"
#>